dc.contributor.author | Jess, DB | |
dc.contributor.author | Snow, B | |
dc.contributor.author | Houston, SJ | |
dc.contributor.author | Botha, GJJ | |
dc.contributor.author | Fleck, B | |
dc.contributor.author | Krishna Prasad, S | |
dc.contributor.author | Asensio Ramos, A | |
dc.contributor.author | Morton, RJ | |
dc.contributor.author | Keys, PH | |
dc.contributor.author | Jafarzadeh, S | |
dc.contributor.author | Stangalini, M | |
dc.contributor.author | Grant, SDT | |
dc.contributor.author | Christian, DJ | |
dc.date.accessioned | 2020-01-23T14:34:50Z | |
dc.date.issued | 2019-12-02 | |
dc.description.abstract | Sunspots are intense collections of magnetic fields that pierce through the Sun’s photosphere, with their signatures extending upwards into the outermost extremities of the solar corona1. Cutting-edge observations and simulations are providing insights into the underlying wave generation2, configuration3,4 and damping5 mechanisms found in sunspot atmospheres. However, the in situ amplification of magnetohydrodynamic waves6, rising from a few hundreds of metres per second in the photosphere to several kilometres per second in the chromosphere7, has, until now, proved difficult to explain. Theory predicts that the enhanced umbral wave power found at chromospheric heights may come from the existence of an acoustic resonator8–10, which is created due to the substantial temperature gradients experienced at photospheric and transition region heights11. Here, we provide strong observational evidence of a resonance cavity existing above a highly magnetic sunspot. Through a combination of spectropolarimetric inversions and comparisons with high-resolution numerical simulations, we provide a new seismological approach to mapping the geometry of the inherent temperature stratifications across the diameter of the underlying sunspot, with the upper boundaries of the chromosphere ranging between 1,300 ± 200 km and 2,300 ± 250 km. Our findings will allow the three-dimensional structure of solar active regions to be conclusively determined from relatively commonplace two-dimensional Fourier power spectra. The techniques presented are also readily suitable for investigating temperature-dependent resonance effects in other areas of astrophysics, including the examination of Earth–ionosphere wave cavities12. | en_GB |
dc.description.sponsorship | Science and Technology Facilities Council (STFC) | en_GB |
dc.description.sponsorship | Invest NI and Randox Laboratories Ltd | en_GB |
dc.description.sponsorship | Spanish Ministry of Economy and Competitiveness | en_GB |
dc.description.sponsorship | European Union Horizon 2020 | en_GB |
dc.description.sponsorship | Research Council of Norway | en_GB |
dc.description.sponsorship | INAF Istituto Nazionale di Astrofisica | en_GB |
dc.description.sponsorship | California State University Northridge | en_GB |
dc.identifier.citation | Published online 2 December 2019 | en_GB |
dc.identifier.doi | 10.1038/s41550-019-0945-2 | |
dc.identifier.grantnumber | 059RDEN-1 | en_GB |
dc.identifier.grantnumber | ST/R000891/1 | en_GB |
dc.identifier.grantnumber | AYA2014-60476-P | en_GB |
dc.identifier.grantnumber | 682462 | en_GB |
dc.identifier.grantnumber | 262622 | en_GB |
dc.identifier.grantnumber | 739500 | en_GB |
dc.identifier.grantnumber | 824135 | en_GB |
dc.identifier.grantnumber | PRIN-INAF-2014 | en_GB |
dc.identifier.uri | http://hdl.handle.net/10871/40550 | |
dc.language.iso | en | en_GB |
dc.publisher | Nature Research | en_GB |
dc.rights.embargoreason | Under embargo until 2 June 2020 in compliance with publisher policy | en_GB |
dc.rights | © The Author(s), under exclusive licence to
Springer Nature Limited 2019 | en_GB |
dc.title | A chromospheric resonance cavity in a sunspot mapped with seismology | en_GB |
dc.type | Article | en_GB |
dc.date.available | 2020-01-23T14:34:50Z | |
dc.description | This is the author accepted manuscript. The final version is available from Nature Research via the DOI in this record | en_GB |
dc.description | Data availability:
The data used in this paper are from the observing campaign entitled ‘The Influence of Magnetism on Solar and Stellar Atmospheric Dynamics’ (NSO-SP proposal T1081; principal investigator: D.B.J.), which employed the ground-based Dunn Solar Telescope, USA, during July 2016. Additional supporting observations were obtained from the publicly available NASA’s Solar Dynamics Observatory (https://sdo.gsfc.nasa.gov) data archive, which can be accessed via http://jsoc.stanford.edu/ajax/lookdata.html. The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request. | en_GB |
dc.description | Code availability:
The numerical code (Lare2D) used in the work can be downloaded from: https://warwick.ac.uk/fac/sci/physics/research/cfsa/people/tda/larexd/ | en_GB |
dc.identifier.eissn | 2397-3366 | |
dc.identifier.journal | Nature Astronomy | en_GB |
dc.rights.uri | http://www.rioxx.net/licenses/all-rights-reserved | en_GB |
dcterms.dateAccepted | 2019-10-16 | |
rioxxterms.version | AM | en_GB |
rioxxterms.licenseref.startdate | 2019-12-02 | |
rioxxterms.type | Journal Article/Review | en_GB |
refterms.dateFCD | 2020-01-23T14:29:39Z | |
refterms.versionFCD | AM | |
refterms.panel | B | en_GB |